MORROW COUNTY, Ore.-The first detection of highly pathogenic avian influenza (HPAI) in Oregon dairy cattle has been confirmed after milk from a Morrow County dairy tested positive.
“While this detection is significant, it is not unexpected given the continued spread of HPAI among dairy cattle nationally,” said Dr. Ryan Scholz, State Veterinarian for the Oregon Department of Agriculture (ODA).
The HPAI in Morrow County was identified through Oregon’s routine statewide milk surveillance system, which tests milk from licensed dairy operations, with preliminary results reported by the Oregon Veterinary Diagnostic Laboratory (OVDL) at Oregon State University on November 6.
The ODA started an on-site investigation and additional samples sent to the United States Department of Agriculture (USDA) National Veterinary Services Laboratory (NVSL) confirmed the positive HPAI results from Morrow County on November 10.
According to the ODA, it is working with the USDA, Oregon Health Authority, Morrow County Public Health officials, OVDL and dairy partners, as the HPAI investigation continues.
The affected dairy was placed under quarantine, restricting animal movement, and disease control measures were put in place following the confirmation of HPAI.
“Oregon’s milk surveillance program worked exactly as intended, identifying this infection quickly and allowing us to respond rapidly without state and federal partners,” said Dr. Scholz. “This detection demonstrates the value of the monitoring and preparedness efforts supported by Oregon’s dairy industry and animal health partners since 2024.”
Oregon’s statewide dairy surveillance program works to detect HPAI early and support rapid response efforts, including allowing state and federal officials to implement disease control measures quickly, according to ODA.
HPAI was first detected in dairy cattle in the United States in 2024 and has been found in multiple states since.
In Yakima County, Washington, 39 confirmed dairy cattle herds have tested positive for avian influenza as of October 30, according to the Washington Department of Agriculture (WSDA).
The first human death attributed to HPAI this year was also reported in Yakima County on November 1.
According to the Yakima Health District, the individual who died had serious underlying health conditions prior to contracting HPAI.
No human cases of HPAI associated with the positive test in Morrow County have been identified and the public health risk remains low, according to the OHA and the Centers for Disease Control and Prevention (CDC).
“With the use of appropriate personal protective equipment, the risk to farm workers remains low,” said Melissa Sutton, M.D., Medical Director, Respiratory Viral Pathogens, OHA. “Our public health approach is focused on ensuring rapid testing and treatment for any individuals who develop symptoms to prevent severe disease.”
According to the ODA, pasteurized milk and dairy products remain safe to consume, as pasteurization inactivates the HPAI virus.
